We’re getting closer to seeing NASA’s Space Launch System heavy lift vehicle roll onto the launch pad. On October 9, the space agency awarded contractor Alliant Techsystems (ATK) a $50 million contract to complete engineering development and risk reduction tests on the rocket that will serve as the SLS’s external booster stages.
At the centre of the SLS system is a liquid-fueled core stage modeled off the space shuttle’s big orange external fuel tank. And, like the shuttle, the core stage will be flanked by two solid rocket boosters; later these solid boosters might be replaced by liquid-fueled ones. SLS will eventually scale up from its initial 70-metric-ton lifting capability to an evolved configuration with a 130-metric-ton lifting capability. This bigger version will have enough power and carry enough fuel to send the Orion capsule to deep-space destinations such as Mars.
For thirty years, the shuttle’s reusable external boosters were built and refurbished between launches by the Morton Thiokol Corporation of Utah. In 2001, Thiokol became a part of ATK, which means the contractor has three decades of experience with solid rocket boosters to bring to the SLS program.
“We are thrilled to have the opportunity to work with NASA to further reduce costs on the SLS program while providing advanced technology to enhance the capability of America’s heavy launch system,” said Charlie Precourt, ATK’s vice president and general manager, Space Launch Division. “We appreciate NASA’s focus on addressing the challenges of enhancing performance.”
Under its new contract, ATK will work from June 2014 to February 2015 on some of the key challenges associated with developing the advanced booster for the SLS. Among the new technologies under development are a lithium-ion battery-powered electric thrust vector control system, a high-performance propellant, a lightweight composite rocket motor case, and an advanced nozzle.
New developments on the SLS’s boosters go beyond those ATK will address under this latest contract. A new human-rated avionics system and flight termination system will come into these new boosters, as well as new insulation, nozzles, and propellant grain structure. Moving from technology to actual construction of the boosters, ATK will approach the new program with the goal of increasing efficiencies in manufacturing.
The new technology ATK develops for the SLS’ boosters will complement existing technology the contractor plans to reuse from the shuttle’s booster program. Existing hardware we can expect to see in the SLS includes the steel case hardware and thrust vector control system hardware. The manufacturing facilities and techniques used to fabricate the boosters will remain the same, as will the test facilities and processing methodology and facilities used at the Kennedy Space Center.
Each of these new technologies are crucial to reduce the booster’s overall cost and help lower risk as NASA moves forwards with its next major rocket. “This program will not only demonstrate a higher-performing booster, it will verify our affordability initiatives, which are key to sustainability as we move forward,” said Precourt. “Our advanced booster design incorporates innovations that deliver greater performance than current NASA requirements, while also providing higher reliability and lower costs.”
By investing in ATK at this early stage, added Precourt, NASA is a step closer to securing a safe and affordable human space exploration program. The new contract will culminate with ATK running a test fire of an integrated booster to demonstrate the new (and reused) technologies in one go.